Combo picture shows Britain's Prince Charles kissing Diana, Princess of Wales during their wedding in London on July 29, 1981 and (on right) Britain's Prince William kissing his wife Kate, Duchess of Cambridge on the balcony of Buckingham Palace on April 29, 2011, in London. (credit -/AFP/Getty Images)

Police officers stand in front of royal supporters on The Mall in London, along the Processional Route, in central London, on April 29, 2011. (credit: PIERRE-PHILIPPE MARCOU/AFP/Getty Images)

Royal Wedding

Britain's Prince William kisses his wife Kate, Duchess of Cambridge, on the balcony of Buckingham Palace, after the wedding service, on April 29, 2011, in London. (credit: LEON NEAL/AFP/Getty Images)

Royal Wedding

Britain's Prince William kisses his wife Kate, Duchess of Cambridge, on the balcony in Buckingham Palace, after the wedding service, on April 29, 2011, in London. AFP (credit: LEON NEAL/AFP/Getty Images)

Royal Wedding

Their Royal Highnesses Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge greet well-wishers from the balcony at Buckingham Palace on April 29, 2011 in London, England. (credit: Peter Macdiarmid/Getty Images)

Royal Wedding

Flags with the royal couple are waved as Prince William and Princess Catherine make the journey by carriage procession to Buckingham Palace following their marriage at Westminster Abbey on April 29, 2011 in London, England. (credit: Sean Gallup/Getty Images)

Royal Wedding

Their Royal Highnesses Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge greet well-wishers from the balcony at Buckingham Palace on April 29, 2011 in London, England. (credit: Peter Macdiarmid/Getty Images)

Royal Wedding

The crowd cheers and waits to see the couple pass pior to the Royal Wedding of Prince William to Catherine Middleton at Westminster Abbey on April 29, 2011 in London, England. (credit: Jasper Juinen/Getty Images)

Royal Wedding

The Queen's Guard march before the royal marriage of Britain's Prince William and Kate Middleton in central London on April 29, 2011. (credit: Paul HackettAFP PHOTO / WPA POOL)

Royal Wedding

Prince William and Princess Catherine greet well-wishers from the balcony at Buckingham Palace on April 29, 2011 in London, England. (credit: Peter Macdiarmid /Getty Images)

Royal Wedding

Thousands of well-wishers from around the world have also flocked to London to witness the spectacle and pageantry of the Royal Wedding and street parties are being held throughout the UK. (credit: Tom Dulat/Getty Images)

Royal Wedding

Prince William and Princess Catherine make the journey by carriage procession to Buckingham Palace following their marriage at Westminster Abbey on April 29, 2011 in London, England. (credit: Sean Gallup /Getty Images)

Maid of Honour Pippa Middleton with bridemaid Margarita Armstrong-Jones make the journey by carriage procession to Buckingham Palace following the marriage of Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge at Westminster Abbey on April 29, 2011 in London, England. (credit: Julian Finney/Getty Images)

Royal Wedding

Prince Harry and Lady Louise Windsor ride in a carriage procession to Buckingham Palace following the marriage of Their Royal Highnesses Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge at Westminster Abbey on April 29, 2011 in London, England. (credit: Sean Gallup/Getty Images)

Royal Wedding

Britain's Prince William and his wife Kate, Duchess of Cambridge, come out of Westminster Abbey in London, after their wedding service, on April 29, 2011. (credit: AFP PHOTO / CARL DE SOUZA)

Royal Wedding

Prince William exchanges rings with his bride Catherine Middleton, now to be known as Catherine, Duchess of Cambridge, inside Westminster Abbey on April 29, 2011 in London, England. (credit: Andrew Milligan - WPA Pool/Getty Images)

PRESS ASSOCIATION Photo. Picture date, Friday 29th April 2011

Photo credit should read: PA/Rota Andrew Milligan

Royal Wedding

Their Royal Highnesses Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge leave the Abbey before making the journey by carriage procession to Buckingham Palace following their marriage at Westminster Abbey on April 29, 2011 in London, England. (credit:Dan Kitwood/Getty Images)

Royal Wedding

Their Royal Highnesses Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge journey by carriage procession to Buckingham Palace following their marriage at Westminster Abbey on April 29, 2011 in London, England. (credit:Sean Gallup/Getty Images)

Royal Wedding

Kate Middleton (L) accompagnied by her father Michael Middleton (2nd L) meets the Dean of Westminster in Westminster Abbey in London for her wedding with Britain's Prince William, on April 29, 2011. (credit: AFP PHOTO / Adrian Dennis )

Prince Harry of Wales and Maid of Honour Pippa Middleton share a joke following the marriage of Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge at Westminster Abbey on April 29, 2011 in London, England. (credit: Chris Jackson/Getty Images)

Royal Wedding

Carole Middleton (L) and Camilla, The Duchess of Cornwall, travel in a Semi-State Landau carriage along the Processional Route to Buckingham Palace, in London, on April 29, 2011. (credit: BEN STANSALL/AFP/Getty Images)

Royal Wedding

Britain's Prince William's wife Kate, Duchess of Cambridge, smiles as they travel in the 1902 State Landau carriage along the Processional Route to Buckingham Palace, in London, on April 29, 2011. (credit: STANSALL/AFP/Getty Images)

Royal Wedding

Camilla, Duchess of Cornwall and Queen Elizabeth II (R) depart for a procession to Buckingham Palace following the marriage of Their Royal Highnesses Prince William Duke of Cambridge and Catherine Duchess of Cambridge at Westminster Abbey on April 29, 2011 in London, England. (credit: Dan Kitwood/Getty Images)

Royal Wedding

Sir Elton John (L) and partner David Furnish arrive to attend the Royal Wedding of Britainâs Prince William and Kate Middleton at Westminster Abbey on April 29, 2011 in London. (credit JASPER JUINEN/AFP/Getty Images)

Royal Wedding

Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge smile following their marriage at Westminster Abbey on April 29, 2011 in London, England. (Photo by Chris Jackson/Getty Images)

Royal Wedding

Prince William, Duke of Cambridge and Catherine, Duchess of Cambridge smile following their marriage at Westminster Abbey on April 29, 2011 in London, England. (credit: Chris Jackson/Getty Images)

Royal Wedding

Philippa Middleton, sister of Kate Middleton and Maid of Honour arrives with the bridemaids and page boys at the West Door of Westminster Abbey in London for the wedding her sister to Britain's Prince William, on April 29, 2011. (credit ODD ANDERSEN/AFP/Getty Images)

Royal Wedding

Reverend Richard Chartres, Lord Bishop of London reads from the pulpit, watched by Prince William and his new bride Catherine Middleton on April 29, 2011 in London, England. The marriage of Prince William, the second in line to the British throne, to Catherine Middleton is being held in London today. The marriage of the second in line to the British throne is to be led by the Archbishop of Canterbury and will be attended by 1900 guests, including foreign Royal family members and heads of state. Thousands of well-wishers from around the world have also flocked to London to witness the spectacle and pageantry of the Royal Wedding. (Photo by Dominic Lipinski - WPA Pool/Getty Images)

Royal Wedding

Prince William and and his new bride Kate at the altar of Westminster Abbey, London, during their wedding service. PRESS ASSOCIATION Photo. Picture date: Friday April 29 2011. Photo credit : Anthony Devlin/PA Wire

Royal Wedding

A royal fan holds British Union Jack flags as people gather to watch the wedding of Britain's Prince William and Kate Middleton on big screens in Hyde Park in central London, on April 29, 2011. (credit CARL COURT/AFP/Getty Images)

Royal Wedding

Prince William and Catherine Middleton during their wedding service in Westminster Abbey on April 29, 2011 in London, England. The marriage of the second in line to the British throne is being led by the Archbishop of Canterbury and will be attended by 1900 guests, including foreign Royal family members and heads of state. Thousands of well-wishers from around the world have also flocked to London to witness the spectacle and pageantry of the Royal Wedding. (Photo by Anthony Devlin - WPA Pool/Getty Images)

Royal Wedding

British soldiers in Afghanistan watch the live broadcast of the Royal wedding at Camp Bastion in Helmand province, on April 29, 2011. Prince William married Kate Middleton in regal splendor at London's Westminster Abbey April 29 as huge crowds and a global TV audience watched Britain's biggest royal celebration for three decades. (credit BAY ISMOYO/AFP/Getty Images)

Royal Wedding

Catherine Middleton is led by her father Michael Middleton down the aisle of Westminster Abbey on April 29, 2011 in London, England. The marriage of Prince William, the second in line to the British throne, to Catherine Middleton is being held in London today. The marriage of the second in line to the British throne is to be led by the Archbishop of Canterbury and will be attended by 1900 guests, including foreign Royal family members and heads of state. Thousands of well-wishers from around the world have also flocked to London to witness the spectacle and pageantry of the Royal Wedding. (Photo by Dominic Lipinski - WPA Pool/Getty Images)

Royal Wedding

A crowd of spectators take photographs near to Buckingham Palace prior to the Royal Wedding of Prince William to Catherine Middleton at Westminster Abbey on April 29, 2011 in London, England. (Photo by Peter Macdiarmid/Getty Images)

Royal Wedding

Tom Pettifer laughs as he arrives with Master William Lowther-Pinkerton, Lady Louise Windsor and Margarita Armstrong-Jones to attend the Royal Wedding of Prince William to Catherine Middleton at Westminster Abbey on April 29, 2011 in London, England. (credit: Le Segretain/Getty Images)

Royal Wedding

Sister of the bride and Maid of Honour Pippa Middleton holds hands with Grace Van Cutsem and Eliza Lopes as they arrive to attend the Royal Wedding of Prince William to Catherine Middleton at Westminster Abbey on April 29, 2011 in London, England. (credit: Pascal Le Segretain/Getty Images)

Royal Wedding

Catherine Middleton arrives for the Royal Wedding of Prince William to Catherine Middleton at Westminster Abbey on April 29, 2011 in London, England. (credit: Dan Kitwood/Getty Images)

Royal Wedding

Prince William of Wales arrives to attend his Royal Wedding to Catherine Middleton at Westminster Abbey on April 29, 2011 in London, England. (credit: Chris Jackson /Getty Images)

Royal Wedding

Royal fans wearing masks of Kate Middleton (R), Prince William (2ndR) and Queen Elizabeth (L) wait for Prince William and his bride Kate Middleton to pass by The Mall in London, on April 29, 2011. (Photo credit MAX NASH/AFP/Getty Images)

Britain's Prince William

(credit: Odd Andersen/AFP/Getty Images)

Britain's Prince William (R) arrives with his brother Prince Harry in a Bentley to Westminster Abbey in London for his wedding to Kate Middleton, on April 29, 2011.

Britain's Queen Elizabeth II at the Royal Wedding

(credit: Paul Ellis/AFP/Getty Images)

Britain's Queen Elizabeth II and the Duke of Edinburgh travel to Westminster Abbey in London, for the wedding of Britain's Prince William and Kate Middleton in London on April 29, 2011.

Camilla, Duchess of Cornwall at the Royal Wedding

(credit: Pascal Le Segretain/Getty Images)

Prince Charles, Prince of Wales and Camilla, Duchess of Cornwall arrive to attend the Royal Wedding of Prince William to Catherine Middleton at Westminster Abbey on April 29, 2011 in London, England. The marriage of the second in line to the British throne is to be led by the Archbishop of Canterbury and will be attended by 1900 guests, including foreign Royal family members and heads of state. Thousands of well-wishers from around the world have also flocked to London to witness the spectacle and pageantry of the Royal Wedding.

Princess Beatrice of York at the royal wedding

(credit: Ben Stansall/AFP/Getty Images)

Princess Beatrice of York waves as she arrives at the West Door of Westminster Abbey for the wedding of Britain's Prince William and Kate Middleton in London on April 29, 2011.

David Beckham and Victoria Beckham arrive to attend the Royal Wedding

(credit: Jasper Juinen-WPA Pool/Getty Images)

David Beckham and Victoria Beckham arrive to attend the Royal Wedding of Prince William to Catherine Middleton at Westminster Abbey on April 29, 2011 in London, England. The marriage of the second in line to the British throne is to be led by the Archbishop of Canterbury and will be attended by 1900 guests, including foreign Royal family members and heads of state. Thousands of well-wishers from around the world have also flocked to London to witness the spectacle and pageantry of the Royal Wedding.

Kate Middleton

(credit: Martin Bureau/AFP/Getty Images)

Kate Middleton (R) travels in a Rolls Royce Phantom VI, accompanied by her father Michael Middleton to Westminster Abbey in London for her wedding to Britain's Prince William, on April 29, 2011.

Philippa Middleton at the Royal Wedding

(credit: Odd Andersen/AFP/Getty Images)

Philippa Middleton, sister of Kate Middleton and Maid of Honour arrives with the bridemaids and page boys at the West Door of Westminster Abbey in London for the wedding her sister to Britain's Prince William, on April 29, 2011.

Royal Wedding

(credit: Pascal Le Segretain/Getty Images)

Catherine Middleton waves to the crowds as her sister and Maid of Honour Pippa Middleton holds her dress next to her father Michael Middleton before walking in to the Abbey to attend the Royal Wedding of Prince William to Catherine Middleton at Westminster Abbey on April 29, 2011 in London, England. The marriage of the second in line to the British throne is to be led by the Archbishop of Canterbury and will be attended by 1900 guests, including foreign Royal family members and heads of state. Thousands of well-wishers from around the world have also flocked to London to witness the spectacle and pageantry of the Royal Wedding.

Kate Middleton

(credit: Ben Stansall/AFP/Getty Images)

Kate Middleton (L) waves as she arrives with her sister, the Maid of Honour Philippa Middleton at the West Door of Westminster Abbey in London for her wedding to Britain's Prince William, on April 29, 2011.

Kate Middleton at the Royal Wedding

(credit: Odd Andersen/AFP/Getty Images)

Kate Middleton waves as she arrives to the West Door of Westminster Abbey in London for her wedding to Britain's Prince William, on April 29, 2011.

Royal Wedding

(credit: Dan Kitwood/Getty Images)

Wedding Guests And Party Make Their Way To Westminster Abbey arrive to attend the Royal Wedding of Prince William to Catherine Middleton at Westminster Abbey on April 29, 2011 in London, England.

Royal Wedding

(credit: Suzanne Plunkett/AFP/Getty Images)

General view in Westminster Abbey before the wedding of Britain's Prince William's marriage to Kate Middleton in central London April 29, 2011.

Royal Wedding

(credit: Suzanne Plunkett - WPA Pool/Getty Images)

Elton John (C), and his partner David Furnish (3L) are seen before the wedding at Westminster Abbey ahead of the Royal Wedding of Prince William to Catherine Middleton at Westminster Abbey on April 29, 2011 in London, England. The marriage of the second in line to the British throne is to be led by the Archbishop of Canterbury and will be attended by 1900 guests, including foreign Royal family members and heads of state. Thousands of well-wishers from around the world have also flocked to London to witness the spectacle and pageantry of the Royal Wedding.

Royal Wedding

(credit: Dominic Lipinski - WPA Pool/Getty Images)

Prince William speaks to his bride, Catherine Middleton as she holds the hand of her father Michael Middleton at Westminster Abbey on April 29, 2011 in London, England. The marriage of Prince William, the second in line to the British throne, to Catherine Middleton is being held in London today. The marriage of the second in line to the British throne is to be led by the Archbishop of Canterbury and will be attended by 1900 guests, including foreign Royal family members and heads of state. Thousands of well-wishers from around the world have also flocked to London to witness the spectacle and pageantry of the Royal Wedding.